I'd chalk up the low diesel reliability to all the emission systems. Before all the Mercedes D's would run forever, million miles. Even the heavy truck engines

I'd chalk up the low diesel reliability to all the emission systems. Before all the Mercedes D's would run forever, million miles. Even the heavy truck engines could reach a million miles. Now the emission systems including EGR, SCR, and DPF, add injectors, plumbing and electronics. The EGR and DPF systems clog up with soot or burn up from regen